I think you've hit the nail on the head when you say these three are "somewhat similar", Tim and for med/high magnification planetary viewing I'd doubt that there's much to choose between them in terms of sharpness, contrast, etc.
They all share the same usability deficiencies, though: small eye lens, short eye relief and narrow fields of view (45 degrees for the UO and the Edmund, and 50 degrees for the TeleVue). After the pleasure you're finding from using a Meade
Super
Wide
Angle, any of these three may feel like you're peering through a keyhole. You'll also find a need for constant tweaking of the dob position to keep the target centred, especially when using a barlow. On the other hand, a barlow will improve the eye relief somewhat, so it's not all bad news.
That thread that Suzy mentions is a VERY good place to do some further in-depth research:
The Best 5mm EP under $200